Radiochemical neutron activation analysis of small lanthanoid concentrations

Two procedures for the radiochemical group separation of lanthanoids have been developed. One is intended for total lanthanoid concentrations below 0.5 ppm, while the other, a faster method is meant for concentrations of about 0.5...2 ppm. Both methods are based on fusion with Na₂O₂ and the hydroxide-fluoride precipitation cycle. In the first one the separation of the principal activities is carried out by means of ion exchange and the Sc is removed through extraction with ether as a thiocyanate complex. In the second method the separation of Sc and other metals is effected by tributylphosphate extraction. Results for USGS standards PCC-1 and DTS-1 analyzed and compared with data found in literature. The precision and accuracy of the results are tested by analyzing USGS standards MAG-a, QLO-1, SCo-1, SDC-1, BHVO-1, RGM-1, STM-1 and SGR-1.